Head-disk interaction sensor integrated with suspension

ABSTRACT

A write-inhibit signal is generated by a head-disk interaction sensor during a write process that is integrated with a suspension of a hard disk drive (HDD) when fly-height modulation of the slider is detected during a write process The suspension load beam includes a dimple and a laminated flexure. The laminated flexure includes a surface that is adapted to receive a slider and a surface that is adapted to contact the dimple. The head-disk interaction sensor is fabricated as part of the laminations of the flexure. The head-disk interaction sensor can be an accelerometer that senses an acceleration of the flexure when the slider contacts the disk of the disk drive and/or a pressure sensor that senses a pressure between the flexure and the dimple when the slider contacts the disk. A write-inhibit circuit is responsive to the sensor signal by inhibiting the write process.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is related to co-pending, co-assigned andconcurrently filed patent application Ser. No. 10/664,296, entitled“Disk Drive With Head-Disk Interaction Sensor Integrated WithSuspension,” which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to disk drives. More particularly, thepresent invention relates to a sensor system for improving writeoperations for a hard disk drive (HDD).

2. Description of the Related Art

FIG. 1 shows an exemplary hard disk drive (HDD) 100 having a magneticread/write (R/W) head (or a recording slider) 101 that includes, forexample, a tunnel-valve read sensor, that is positioned over a selectedtrack on a magnetic disk 102. As the fly-height of slider 101 becomessmaller, the chance of slider 101 hitting asperities on disk 102, forexample, disk defects, particles, and/or lubricant bumps, becomesgreater, resulting in a higher probability of fly-height modulation,i.e., “slider jump-up”. When fly-height modulation occurs during a writeprocess, that portion of data being written during slider jump-up can belost because the data is not properly written on the disk due to greaterthan expected write-head-to-disk distance. There is no current techniqueavailable for detecting fly-height modulation during a write process.Consequently, write processes are performed essentially “blind” with thehope that the data is properly written on the disk.

Conventional approaches for minimizing slider modulation includeminimization of head-disk interaction by, for example, reducing thetake-off height of a disk, reducing the number of particles, and usingless mobile lubricant on the disk. These approaches, however, will reachtheir respective limits for minimizing head-disk interaction as sliderfly-height is further reduced.

Consequently, what is needed is a technique for detecting sliderfly-height modulation during a write process. Further, what is needed isa technique for inhibiting a write operation when slider fly-heightmodulation is detected.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a technique for detecting sliderfly-height modulation during a write process. Additionally, the presentinvention provides a technique for inhibiting a write operation whenslider fly-height modulation is detected.

The advantages of the present invention are provided by a suspension fora disk drive having a suspension load beam having a dimple and alaminated flexure. The laminated flexure is coupled to the suspensionload beam and has a surface that is adapted to receive a slider and asurface that is adapted to contact the dimple. According to theinvention, the flexure includes a head-disk interaction sensor thatoutputs a sensor signal when the slider contacts a disk of the diskdrive. One embodiment of the head-disk interaction sensor is anaccelerometer that senses an acceleration of the flexure that isgenerated by the slider contacting the disk of the disk drive. Theaccelerometer includes a piezoelectric material layer and a conductivematerial layer that are each formed as a layer of the laminated flexureand are each patterned to substantially correspond to a top surface of aback portion of the slider.

An alternative or an additional embodiment of the head-disk interactionsensor is a pressure sensor that senses a pressure between the flexureand the dimple that is generated by the slider contacting the disk ofthe disk drive. One configuration of the pressure sensor includes apiezoelectric material layer and a conductive material layer that areeach formed as a layer of the laminated flexure and each are patternedto substantially correspond to a surface region of the flexurecorresponding to the dimple. One pattern is substantially a squareshape. An alternative pattern is a substantially circular shape. Thepiezoelectric material layer generates a voltage between a top portionand a bottom portion of the piezoelectric material layer when the slidercontacts the disk of the disk drive that corresponds to a magnitude of aforce with which the slider contacts the disk of the disk drive.

An alternative configuration of the accelerometer includes apiezoelectric material layer and a conductive material layer that areeach formed as a layer of the laminated flexure and are each patternedto form a first region and a second region. The first and second regionsrespectively correspond to a front portion and a back portion of theslider and respectively corresponding to first and second surfaceregions of the surface of the flexure adapted to contact the dimple. Thefirst region of the piezoelectric material layer generates a firstvoltage between a top portion and a bottom portion of the first regionof the piezoelectric material layer when the slider contacts the disk ofthe disk drive. Similarly, the second region of the piezoelectricmaterial layer generates a second voltage between a top portion and abottom portion of the second region of the piezoelectric material layerwhen the slider contacts the disk of the disk drive. The first andsecond voltages respectively generated between the top portions and thebottom portions of the first and second regions of the piezoelectricmaterial layer each correspond to a magnitude of a force with which theslider contacts the disk of the disk drive. A pitch mode of the slidercan be determined based on a difference between the first voltage andthe second voltage. Additionally, a first bending mode of a body of theslider body can be determined based on a sum of the first and secondvoltages.

The suspension of the present invention further includes a write-inhibitcircuit that is responsive to the sensor signal by inhibiting a writeoperation of the disk drive. The write-inhibit circuit includes a filtercircuit that condition the sensor signal. One embodiment of the filtercircuit is a low-pass filter having a passband that is greater thanabout 20 kHz. Another embodiment of the filter circuit is a high-passfilter having a passband that is less than about 2 MHz. Yet anotherembodiment of the filter circuit is a bandpass filter having a passbandbetween about 20 kHz and about 2 MHz. Further, the filter circuit can bea bandpass filter having a passband corresponding to about a pitchfrequency of the slider. For example, the filter circuit can have anarrow passband at about 200 kHz. Further still, the filter circuit canbe a bandpass filter having a passband corresponding to about a bendingmode frequency of a body of the slider. For example, the filter circuitcan have a narrow passband at about 1.6 MHz. Alternatively, the filtercircuit can be a passband filter having a passband that includes about200 kHz and about 1.6 MHz.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not bylimitation in the accompanying figures in which like reference numeralsindicate similar elements and in which:

FIG. 1 shows an exemplary disk drive having a magnetic read/write head;

FIG. 2A shows a side view of a slider, a suspension and a flexure havinga first exemplary embodiment of an integrated accelerometer according tothe present invention;

FIG. 2B shows a top view of a piezoelectric material layer of the firstexemplary embodiment of the integrated accelerometer shown in FIG. 2A;

FIG. 2C shows a cross-sectional view of the first exemplary embodimentof accelerometer according to the present invention shown in FIG. 2A asview A;

FIG. 3A shows a side view of a slider, a suspension and a flexure havingan exemplary embodiment of an integrated pressure sensor for detectingdimple pressure according to the present invention;

FIG. 3B shows a top view of a piezoelectric material layer of theexemplary embodiment of the integrated pressure sensor for detectingdimple pressure according to the present invention shown in FIG. 3A;

FIG. 3C shows a cross-sectional view of the first exemplary embodimentof a pressure sensor for detecting dimple pressure according to thepresent invention shown in FIG. 3A as view B;

FIG. 4A shows a side view of a slider, a suspension and a flexure havinga second exemplary embodiment of an integrated accelerometer fordetecting vertical acceleration and first pitch mode of the slideraccording to the present invention;

FIG. 4B shows a top view of a piezoelectric material layer of the secondexemplary embodiment of the integrated accelerometer shown in FIG. 4A;

FIG. 5A shows a side view of a slider, a suspension and a flexure havinga third exemplary embodiment of an integrated accelerometer fordetecting pitch motion and bending motion of the slider according to thepresent invention;

FIG. 5B shows a top view of a piezoelectric material layer of the thirdexemplary embodiment of the integrated accelerometer shown in FIG. 5A;and

FIG. 6 shows a schematic block diagram of a circuit for detectinghead-disk interaction and enabling write-inhibit followed by a datarewrite according to the present invention

DETAILED DESCRIPTION OF THE INVENTION

The present invention detects head-disk interaction in an HDD by usingat least one sensor that is integrated with suspension. Slider motioncaused by Head-Disk Interference (HDI) is detected by using a force (orpressure) sensor for monitoring the force (or pressure) between the backof the slider and the suspension dimple, and/or by using anaccelerometer for measuring the acceleration of the slider. Both thepressure sensor and the acceleration sensor are integrated with asuspension having a laminated flexure.

The signal output from the sensors includes both air-flow-related noiseand write-current-related noise. Noise that is caused by air-flowtypically has a very low frequency component, i.e., less than 20 kHz.Noise that is caused by write current typically has a very highfrequency, i.e., greater than 2 Mhz. Accordingly, the present inventionpasses the frequency component at the pitch mode frequency of the sliderat approximately 200 kHz, and at the first bending mode frequency of theslider body at approximately 1.7 MHz, while removing low-frequency noisecaused by air flow and high-frequency noise caused by write current.

Tables 1-3 below respectively set forth simulation results of theexpected acceleration of the R/W element of a slider and the expectedforce applied to a dimple of a suspension for soft, medium-soft and hardasperities on a disk

TABLE 1 Slider/Lubrication Interaction Remarks Force: Fz 1.5 mN Fx 1.5mN Duration: 6 μs Assumed 0.5 μs risetime, 5.0 μs peak duration, and 0.5μs decay. Results: FHM at R/W 10 nm Acceleration at R/W 8,000 m/s² 200kHz oscillation Acceleration at dimple 2,400 m/s² Stress (x) 200,000N/m/m Strain (x) 4.00 × 10⁻⁷ Force at the dimple 0.6 mN

TABLE 2 Slider/Medium Hardness Asperity Interaction Remarks: Force: Fz1.5 mN Fx 1.5 mN Duration: 1 μs Assumed 0.2 μs risetime, 0.6 μs peakduration, and 0.2 μs decay. Results: FHM at R/W 5 nm Acceleration at R/W26,000 m/s² 200 kHz and 1.7 MHz oscillations Acceleration at dimple7,000 m/s² Stress (x) 75,000 N/m/m Strain (x) 1.9 × 10⁻⁷ Force at thedimple 0.5 mN

TABLE 3 Slider/Hard Asperity Interaction Remarks Force: Fz 1.5 mN Fx 1.5mN Duration: 0.5 μs Assumed 0.1 μs risetime, 0.3 μs peak duration, and0.1 μs decay. Results: FHM at R/W 1.4 nm Acceleration at R/W 30,000 m/s²1.7 MHz oscillation Acceleration at dimple 8,000 m/s² Stress (x) 80,000N/m/m 1.7 MHz Strain (x) 2.0 × 10⁻⁷ 1.7 MHz Force at the dimple 0.22 mN

Simulated acceleration at the R/W element is calculated to be between8,000 to 30,000 m/s² (or 800-3000 G). The simulated force applied to adimple is calculated to be between 0.22 mN to 0.6 mN.

FIG. 2A shows a side view of a slider, a suspension and a flexure havinga first exemplary embodiment of an integrated accelerometer according tothe present invention. FIG. 2B shows a top view of a piezoelectricmaterial layer of the first exemplary embodiment of the integratedaccelerometer shown in FIG. 2A. In FIG. 2A, a slider 201 is attached toa suspension flexure 202 in a well-known manner. Flexure 202 is alaminated flexure, such as disclosed by U.S. Pat. No. 4,996,623 toErpelding et al. or by U.S. Pat. No. 5,491,597 to Bennin et al., both ofwhich are incorporated by reference herein. Flexure 202 contacts asuspension load beam 203 through a dimple 204, which provides a gimbalfunction. An accelerometer 205 is fabricated as an integral part offlexure 202.

FIG. 2C shows a cross-sectional view of the first exemplary embodimentof accelerometer 205 according to the present invention shown in FIG. 2Aas view A. Flexure 202 includes a metal layer 206 that is formed from,for example, stainless steel. A first insulative material layer 207 isformed on metal layer 206 using well-known techniques. First insulativelayer 207 is formed from, for example, polyimide. A first conductivematerial layer 208 is formed on first insulative layer 207 usingwell-known techniques and is formed from, for example, copper. Apiezoelectric material layer 209, such as Poly(vinilyden fluoride)(PVDF), is formed on first conductive material layer 208 as a film usingwell-known techniques. A second conductive material layer 210 is formedon piezoelectric material layer 209 using well-known techniques and isformed from, for example, copper. A second insulative layer 211 isformed on second conductive layer 210 using well-known techniques and isformed from, for example, polyimide. After flexure 202 is attached tosuspension load beam 203, slider 201 is glued to flexure 202 andintegrated accelerometer 205.

Piezoelectric material layer 209 and the first and second conductivematerial layers 208 and 210 (not shown in FIG. 2B), which are formed onboth sides of piezoelectric material layer 209, are patterned so thatthese three layers correspond to only the top of the trailing edge ofslider 201 (i.e., the R/W element end of slider 201). When HDI occursand a force 212 is applied to the trailing edge of slider 201, slider201 typically moves in a pitch direction, as indicated by arrows 213 and214. The resulting acceleration compresses piezoelectric material layer209 caused by the inertia and rigidity of metal layer 206. Whenpiezoelectric material layer 209 is compressed, a voltage difference ofa few millivolts is generated across piezoelectric material layer 209,as depicted by voltage V. The voltage difference is easily detectedusing a well-known voltage detection technique. By monitoring thevoltage generated across piezoelectric material layer 209, theacceleration imparted to slider 201 by HDI can be determined. Detectionaccuracy can be further improved by adding a low-pass and/or high-pass,and/or peak filter between the output of piezoelectric material layer209 and the voltage detection device. The best center frequency for apeak filter is at the pitch frequency of the slider.

FIG. 3A shows a side view of a slider, a suspension and a flexure havingan exemplary embodiment of an integrated pressure sensor for detectingdimple pressure according to the present invention. FIG. 3B shows a topview of a piezoelectric material layer of the exemplary embodiment ofthe integrated pressure sensor for detecting dimple pressure accordingto the present invention shown in FIG. 3A. In FIG. 3A, a slider 301 isattached to a suspension flexure 302 in a well-known manner. Flexure 302is a laminated flexure, such as disclosed by U.S. Pat. No. 4,996,623 toErpelding et al. or by U.S. Pat. No. 5,491,597 to Bennin et al., both ofwhich are incorporated by reference herein. Flexure 302 contacts asuspension load beam 303 through a dimple 304, which provides a gimbalfunction. A pressure sensor 305 is fabricated as an integral part offlexure 302.

FIG. 3C shows a cross-sectional view of the exemplary embodiment of apressure sensor 305 for detecting dimple pressure according to thepresent invention shown in FIG. 3A as view B. Flexure 302 includes ametal layer 306 that is formed from, for example, stainless steel. Afirst insulative material layer 307 is formed on metal layer 306 using awell-known technique. First insulative layer 307 is formed from, forexample, polyimide. A first conductive material layer 308 is formed onfirst insulative layer 307 using a well-known technique and is formedfrom, for example, copper. A piezoelectric material layer 309, such asPVDF, is formed on first conductive material layer 308 as a film using awell-known technique. A second conductive material layer 310 is formedon piezoelectric layer 309 using a well-known technique and is formedfrom, for example, copper. A second insulative layer 311 is formed onsecond conductive material layer 310 using a well-known technique and isformed from, for example, polyimide. After flexure 302 is attached tosuspension load beam 303, slider 301 is glued to flexure 302 andintegrated pressure sensor 305.

Piezoelectric material layer 309 and the first and second conductivematerial layers 308 and 310 (not shown in FIG. 3B), which are formed onboth sides of piezoelectric material layer 309, are patterned so thatthese three layers exist around dimple contact region 314. FIG. 3B showsa substantially circularly shaped patterning, although it should beunderstood that alternative shapes can also be used. When HDI occurs anda force 312 is applied to the trailing edge of slider 301, slider 301moves toward dimple 304 along the z-axis, the inertia of the suspensioncompresses piezoelectric material layer 309, resulting in a detectablevoltage of several millivolts across piezoelectric material layer 309.Detection accuracy can be further improved by adding a low-pass and/orhigh-pass, and/or peak filter between the output of piezoelectricmaterial layer 309 and the voltage detection device. The best centerfrequency for a peak filter is at the pitch frequency of the slider.

FIG. 4A shows a side view of a slider, a suspension and a flexure havinga second exemplary embodiment of an integrated accelerometer fordetecting vertical acceleration and the first pitch mode of the slideraccording to the present invention. FIG. 4B shows a top view of apiezoelectric material layer of the second exemplary embodiment of theintegrated accelerometer shown in FIG. 4A. In FIG. 4A, a slider 401 isattached to a suspension flexure 402 in a well-known manner. Only theportion of flexure 402 corresponding to the integrated accelerometer isshown in FIG. 4A. Flexure 402 is a laminated flexure, such as disclosedby U.S. Pat. No. 4,996,623 to Erpelding et al. or by U.S. Pat. No.5,491,597 to Bennin et al., both of which are incorporated by referenceherein. Flexure 402 contacts a suspension load beam 403 through a dimple404, which provides a gimbal function. An accelerometer 405 isfabricated as an integral part of flexure 402.

Flexure includes a metal layer 406 that is formed from, for example,stainless steel. A first insulative material layer 407 is formed onmetal layer 406 using a well-known technique and is formed from, forexample, polyimide. A first conductive material layer 408 is formed onfirst insulative layer 407 using a well-known technique and is formedfrom, for example, copper. A piezoelectric material layer 409, such asPVDF, is formed on first conductive material layer 408 as a film using awell-known technique. A second conductive material layer 410 is formedon piezoelectric layer 409 using a well-known technique and is formedfrom, for example, copper. A second insulative layer 411 is formed onsecond conductive layer 410 using a well-known technique and is formedfrom, for example, polyimide. After flexure 402 is attached tosuspension load beam 403, slider 401 is glued to flexure 402 andintegrated accelerometer 405.

Piezoelectric material layer 409 and the first and second conductivematerial layers 408 and 410 (not shown in FIG. 4B) formed on both sidesof piezoelectric material layer 409 are patterned so that these threelayers corresponding to the entire top side of slider 401 around dimplecontact region 414. FIG. 4B shows the patterning of piezoelectricmaterial layer 409. While FIG. 4B shows a substantially square shapedpatterning, it should be understood that alternative shapes can also beused. Accelerometer 405 covers entire top side of slider 401 and therebyprovides a substantially flat bonding surface on the top side of slider401 for bonding slider 401 to flexure 402. Accelerometer 405 detects thetranslation acceleration of slider 401 in the z-axis direction and thefirst bending mode amplitude of slider body 401. When HDI occurs andslider 401 moves toward dimple 404, the inertia of the suspensioncompresses piezoelectric material layer 409, resulting in a detectablevoltage of several millivolts across piezoelectric material layer 409.Detection accuracy can be further improved by adding a low-pass and/orhigh-pass, and/or peak filter between the output of piezoelectricmaterial layer 409 and the voltage detection device. The best centerfrequency for a peak filter is at the pitch frequency of the slider.

FIG. 5A shows a side view of a slider, a suspension and a flexure havinga third exemplary embodiment of an integrated accelerometer fordetecting pitch motion and bending motion of the slider according to thepresent invention. FIG. 5B shows a top view of a piezoelectric materiallayer of the third exemplary embodiment of the integrated accelerometershown in FIG. 5A. In FIG. 5A, a slider 501 is attached to a suspensionflexure 502 in a well-known manner. Only the portion of flexure 502corresponding to the integrated accelerometer is shown in FIG. 5A.Flexure 502 contacts a suspension load beam 503 through a dimple 504,which provides a gimbal function. Accelerometers 505 a and 505 b arefabricated as an integral part of slider 501.

Flexure 502 includes a metal layer 506 that is formed from, for example,stainless steel. A first insulative material layer 507 is formed onmetal layer 506 using a well-known technique. First insulative layer 507is formed from, for example, polyimide. A first conductive layer 508 isformed on first insulative layer 507 and is formed from, for example,polyimide. Piezoelectric material layer 509 is formed on firstconductive material layer 508. Piezoelectric material layer 509 isformed as a film from, for example, PVDF, using a well-known technique.Two second conductive material layers 510 a and 510 b are formed onpiezoelectric material layer 509 using a well-known technique and areformed from, for example, copper. Second conductive material layers 510a and 510 b are patterned to be separate, as shown in FIG. 5B. A secondinsulative layer 511 is formed on second conductive material layers 510a and 510 b using a well-known technique and is formed from, forexample, polyimide. After flexure 502 is attached to suspension loadbeam 503, slider 501 is glued to flexure 502 and integratedaccelerometer 505.

The first and second conductive material layers 510 a and 510 b arepatterned so that they respectively correspond to the front and backsides of the top side of slider 501 around dimple contact region 514, asshown in FIG. 5B. Additionally or alternatively, piezoelectric materiallayer 508 can be patterned as shown in FIG. 5B. Second conductivematerial layer 510 can also be patterned as shown in FIG. 5B. Whenpiezoelectric material layer 508 is patterned as shown in FIG. 5B, atleast one of the first conductive material layer 508 or the secondconductive material layer 510 must be patterned as shown in FIG. 5B. Inany alternative configuration, accelerometer 505 a corresponds to thefront, or leading, side of the top of slider 501 and accelerometer 505 bcorresponds to the back, or trailing, side of the top of slider 501,thereby providing a mostly flat bonding surface on the top side ofslider 501 for bonding slider 501 to flexure 502. The pitch mode ofslider 501 can be detected based on the difference of measured voltagesV1 and V2, i.e., V1−V2. The first bending mode of slider body 501 can bedetected based on the sum of voltages V1 and V2, i.e., V1+V2. Detectionaccuracy can be further improved by adding a low-pass and/or high-pass,and/or peak filter between the output of piezoelectric material layer509 and the voltage detection device.

FIG. 6 shows a schematic block diagram of a circuit 600 for detectingHDI according to the present invention. FIG. 6 shows a slider 601 thatis attached in a well-known manner to a laminated suspension flexure 602having an integrated accelerometer and/or pressure sensor according tothe present invention. Flexure 602 contacts a suspension load beam 603,of which only a portion is shown in FIG. 6, through a dimple 604, whichprovides a gimbal function. An HDI sensor 605 is fabricated as anintegral part of flexure 602, as described above. HDI sensor 605 can bean accelerometer and/or a pressure sensor, also as described above.

When there is a head-disk interaction event, slider 601 physicallyvibrates in a vertical direction. HDI sensor 605, which has beenintegrated with flexure 602, detects the vibration and generates acorresponding sensor signal 606. The vibration mode of slider 601 can beeither a single impulse when, for example, slider 601 contacts a hardasperity, or a periodic oscillation at the pitch frequency of slider 601when, for example, when slider 601 makes contact with the disk (notshown in FIG. 6) through an abnormally thick lubricant. Sensor signal606 is input to a signal amplifier 607. The output of signal amplifier607 is coupled to a filter circuit 608. Filter circuit 608 can be ahigh-pass filter so that low-frequency noise is rejected. The cut-offfrequency the high-pass filter should preferably be set to be below thepitch-mode frequency of slider 601 so that sensor signal 606 generatedin response to the slider pitch motion passes through filter circuit608. Filter circuit 608 can also be a low-pass filter so that electricalnoise generated by the write current can be rejected. Usually, the writecurrent has frequency content that is greater than 1 MHz, whereas theslider pitch-mode frequency is a few hundred of kilohertz. Thus, it ispreferred to set the cut-off frequency of low-pass filter to a frequencythat is between typical write current frequency and slider pitch-modefrequency. It is even more preferable to combine both a low-pass and ahigh-pass filter. Alternatively, a bandpass filter can be used that onlytransmits a sensor signal having particular frequency. When a bandpassfilter is used, it is preferred to select the pitch mode frequency ofslider 601. The sequential order of signal amplifier 607 and filtercircuit 608 can be reversed, that is, the signal can be first filteredand then amplified.

After the sensor signal has been conditioned by filter circuit 608, thesignal amplitude is input to a comparator circuit 609. Comparatorcircuit 609 compares the conditioned sensor signal with a predeterminedthreshold value 610. When the amplitude of the conditioned sensor signalis greater than threshold value 610, comparator circuit 609 generates awrite inhibit signal 611. When an HDD controller 612 (or a read/writechannel that controls the write process) receives write-inhibit signal611, HDD controller 612 immediately stops the write current that isbeing output to the magnetic head (not shown in FIG. 6) so that the headis the proper distance from the disk during the write process.Additionally, HDD controller 612 stops the write current so that data onan adjacent track is not mistakenly overwritten because sometimes HDIcauses off-track motion of the write head. Subsequently, whenwrite-inhibit signal is removed, controller 612 re-tries to write thesame data to the same location.

Although the foregoing invention has been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications may be practiced that are within the scope ofthe appended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

1. A suspension for a disk drive, comprising: a suspension load beamhaving a dimple; and a laminated flexure coupled to the suspension loadbeam, the flexure having a surface adapted to receive a slider and asurface adapted to contact the dimple, the flexure including a head-diskinteraction sensor outputting a sensor signal when the slider contacts adisk of the disk drive.
 2. The suspension according to claim 1, whereinthe head-disk interaction sensor is an accelerometer sensing anacceleration of the flexure generated by the slider contacting the diskof the disk drive.
 3. The suspension according to claim 2, wherein thehead-disk interaction sensor further includes a pressure sensor sensinga pressure between the flexure and the dimple generated by the slidercontacting the disk of the disk drive.
 4. The suspension according toclaim 2, wherein the accelerometer includes a piezoelectric materiallayer and a conductive material layer, the piezoelectric material layerand the conductive material layer each being formed as a layer of thelaminated flexure and each being patterned to substantially correspondto a top surface of a back portion of the slider.
 5. The suspensionaccording to claim 1 wherein the head-disk interaction sensor is apressure sensor sensing a pressure between the flexure and the dimplegenerated by the slider contacting the disk of the disk drive.
 6. Thesuspension according to claim 5, wherein the pressure sensor includes apiezoelectric material layer and a conductive material layer, thepiezoelectric material layer and the conductive material layer eachbeing formed as a layer of the laminated flexure and each beingpatterned to substantially correspond to a surface region of the flexurecorresponding to the dimple.
 7. The suspension according to claim 6,wherein the piezoelectric material layer generates a voltage between atop portion and a bottom portion of the piezoelectric material layerwhen the slider contacts the disk of the disk drive, the voltagegenerated between the top portion and the bottom portion of thepiezoelectric material layer corresponding to a magnitude of a forcewith which the slider contacts the disk of the disk drive.
 8. Thesuspension according to claim 6, wherein the piezoelectric materiallayer and the conductive material layer are patterned to be asubstantially square shape.
 9. The suspension according to claim 6,wherein the piezoelectric material layer and the conductive materiallayer are patterned to be a substantially circular shape.
 10. Thesuspension according to claim 5, wherein the pressure sensor includes apiezoelectric material layer and a conductive material layer that areeach formed as a layer of the laminated flexure, the piezoelectricmaterial layer and the conductive material layer each being patterned toform a first region and a second region, the first and second regionsrespectively corresponding to a front portion and a back portion of theslider and respectively corresponding to first and second surfaceregions of the surface of the flexure adapted to contact the dimple. 11.The suspension according to claim 10, wherein the first region of thepiezoelectric material layer generates a first voltage between a topportion and a bottom portion of the first region of the piezoelectricmaterial layer when the slider contacts the disk of the disk drive, thesecond region of the piezoelectric material layer generates a secondvoltage between a top portion and a bottom portion of the second regionof the piezoelectric material layer when the slider contacts the disk ofthe disk drive, the first and second voltages respectively generatedbetween the top portions and the bottom portions of the first and secondregions of the piezoelectric material layer each corresponding to amagnitude of a force with which the slider contacts the disk of the diskdrive, and wherein a pitch mode of the slider is determined based on adifference between the first voltage and the second voltage.
 12. Thesuspension according to claim 10, wherein the first region of thepiezoelectric material layer generates a first voltage between a topportion and a bottom portion of the first region of the piezoelectricmaterial layer when the slider contacts the disk of the disk drive, thesecond region of the piezoelectric material layer generates a secondvoltage between a top portion and a bottom portion of the second regionof the piezoelectric material layer when the slider contacts the disk ofthe disk drive, the first and second voltages respectively generatedbetween the top portions and the bottom portions of the first and secondregions of the piezoelectric material layer each corresponding to amagnitude of a force with which the slider contacts the disk of the diskdrive, and wherein a first bending mode of a body of the slider body canbe determined based on a sum of the first and second voltages.
 13. Thesuspension according to claim 1, further comprising a write-inhibitcircuit responsive to the sensor signal by inhibiting a write operationof the disk drive.
 14. The suspension according claim 13, wherein thewrite-inhibit circuit includes a filter circuit conditioning the sensorsignal.
 15. The suspension according to claim 14, wherein the filtercircuit is a low-pass filter having a passband that is greater thanabout 20 kHz.
 16. The suspension according to claim 14, wherein thefilter circuit is a high-pass filter having a passband that is less thanabout 2 MHz.
 17. The suspension according to claim 14, wherein thefilter circuit is a bandpass filter having a passband between about 20kHz and about 2 MHz.
 18. The suspension according to claim 14, whereinthe filter circuit is a bandpass filter having a passband correspondingto about a pitch frequency of the slider.
 19. The suspension accordingto claim 14, wherein the filter circuit is a passband filter having anarrow passband at about 200 kHz.
 20. The suspension according to claim14, wherein the filter circuit is a bandpass filter having a passbandcorresponding to about a bending mode frequency of a body of the slider.21. The suspension according to claim 14, wherein the filter circuit isa passband filter having a narrow passband at about 1.6 MHz.
 22. Thesuspension according to claim 14, wherein the filter circuit is apassband filter having a passband that includes about 200 kHz and about1.6 MHz.